Polarizing Filter Question

Post by **Nick** » Thu Feb 20, 2003 6:24 pm

Should I get a regular polarizing filter or a circular polarizing filter? I have a Canon 1014 xls and I'm filming stuff in sunny Texas.

Nick

Post by **S8 Booster** » Thu Feb 20, 2003 6:38 pm

This isnÃ‚Â´t a foolproof advice but I do have some experience with both kind of filters with a 1014 XL-S.

Some 15 years ago I shot some K40 film with a standard polarizer and in bright light sunny or light overcast the images came out great, not to say exceptional and very grain free. A problem might arise when a very bright object appears like a white T-shirt in low light and a dark background. The bright parts goes easily to overexposure. I would recommend to step down the exposure some by 1/3 or 2/3 of a stop but I recommend test in advance if possible.

Recently I bought a Hoya CIR Polarizer and I have an impression that this did not work as well as the standard with this setup. However, not being able to do a side by side test it is just an impression.

I think the Standard Polarizer with the 1014 turned the K40 into something totally different and the images when projected always reminds me of the impression I get from a Cinema movie in colour saturation etc. Very grain free.

The light certainly being different in Texas and Norway but I think it is worth a try.

I used the built in Auto Exposure during my tests.

R

Post by **Nick** » Thu Feb 20, 2003 7:03 pm

S8 Booster,

Thanks for the advice. I will try this out soon!

Cheers,
Nick

Post by **jessh** » Fri Feb 21, 2003 5:20 am

Whenever you use a camera with a prism in it, such as the Super8 camera you have, you are suposed to use a circular polarized filter. If you use a regular polarized filter you may have problems with the viewfinders image being different than what reaches the film and/or the lightmeter being inacurate.

~Jess

Post by **Lucas Lightfeat** » Fri Feb 21, 2003 12:10 pm

Very interesting Jess - makes sense really - the prism has a 45 degree angled lens on it, so obviously it will affect the polarisation effect, which is designed to remove glare from reflective surfaces.

But why is a circular filter any different from a square filter?

Lucas

Post by **S8 Booster** » Fri Feb 21, 2003 1:02 pm

Never had any problems with either focusing or exposure even at extreme closups with the stadard filter. However, in lower light, f1.4 - 2.8 a slight overexposure can appear on scenes with wide latitude requirement if the high level is bright white or near.

My best takes ever were shot with the standard Polarizer.
I am counting my fingers on if

dare to send this precious stuff to Andreas for WP transfer.

000 001 START
000 002 If -> yes -> then GOTO 000 003 If NO GOTO 000 005.
000 003 post here.
000 004 YouÃ‚Â´ll see.
000 005 END.

Not anxious for the transfer just the transport method to and from.

R

Post by **S8 Booster** » Fri Feb 21, 2003 1:11 pm

Just an additional tips:

If you have a couple of Polarized sunglasses it is easy to check the position of the filter and/or simply mark it because it is free rotating when mounted. This way it is always possible to keep it in "right" position vs the prisms etc.

Two polarized glasses on top of another at 90Ã‚Â° rotation will block totally. for reference.

R

YouTube · Post by **Andreas Wideroe** » Fri Feb 21, 2003 2:03 pm

Here's an example of K40 film I shot in August-02 with a circular polarizing filter:

ftp://ftp.filmshooting.com/upload/video/mpg/akeroya.mpg

I bought the filter (52mm) from Japan Photo (which is a large chain of photo-dealers in Norway). The filter could be turned allowing different types of light through. I like it, but as Vidar says, things can easily be overexposed. The film was shot with my Minolta Autopak-8 K11 camera and transferred to video with the Video WorkPrinter 3.

/Andreas

Post by **Nick** » Fri Feb 21, 2003 7:50 pm

Hi Guys,

Thanks for even more information. Now I will have to go buy both types of polarizing filters and run tests with color and black and white film. I thought I'd be able to get off cheap and buy the regular type. If anyone can suggest a filter brand that is decent quality please let me know.

Nick

Post by **S8 Booster** » Fri Feb 21, 2003 9:58 pm

The only cheap filter I know of in Norway is the Hakuba (Japanese name at least) which probably is the same filter as Andreas uses.

Som info available here: http://www.japanphoto.no/asp/main.asp?node=16

My 72mm Hoya CIR cots 3+x the price of the Hakuba for reference so I would rather bought 2 Hakubas if I knew the price then.

R

Post by **Maurizio Di Cintio** » Sat Feb 22, 2003 4:10 pm

Hi, Nick
I think jessh has set the problem in its most effective terms: it is not a problem of definition or exposure or whatever: it's just that a linear pola will not work on certain S/8 cameras: it depends on how the viwfinder/expusere system prisms are manufatured: actual example: a linear pola works perfectly on my Nizo Integral 5, but it doesn't on my Nizo 6080.

The only way to know is to screw the filter on the lens before you buy it: if it's good the viwfinder will still work with a linear polarizer, though it will show a little darker. Otherwise go for a circular. If you can wait: I have a Canon like yours but I never tried it with a polarizer. Let me try it (it's in another apartment) and I'll let you know tomorrow,

Ciao.

Post by **S8 Booster** » Sun Feb 23, 2003 12:55 am

The 1014 XL-S works well with both standard and CIR POL filters.
I have tested both. (Shot film too)

Just bevare that as far as the light filtering in concerned the filter do have a linear function and you need to find out the directions of this to get full use of it. It need to be rotated to find the right postion vs the light reflexes or source. As said before if you place 2 polarizeres on top of each other by 90Ã‚Â° directional deviation they will block totally. Just make sure you know the linear direction of the filters and they should work with any camera. Anyway a viewfinder check should be OK for verifying.

Actually when you attach the filters on the lens you may see minor variation in brightness in the viewfinder depending on the filter position. May be useful for specialized effects.

My shooting Procedure:
Adjust focal length.
Adjust Focus
Adjust polarizer position by rotation

R

Post by **S8 Booster** » Sun Feb 23, 2003 10:16 am

Suggestion:

If in doubt bring your camera to a photo dealer and hold ANY size polarizer in front of of the lens and check.

If found some info on the WEB that sort of confirms my impression that linear Polarizers do a better job than the CIR ones so go for a linear at least.

R

Guest · Post by **Guest** » Sun Feb 23, 2003 10:45 pm

Can anyone tell me the difference between a "regular polarizing filter" and a "circular polarizing filter"? All of my photography books talk about polarizing filters in general, with no subtypes mentioned.

The term "circular polarizing filter" seems like an oxymoron. Circularly polarized light is the same as unpolarized light. Each photon is polarized of course but there is a random mix of polarities in all directions. Once light is polarized I would not think any filter would restore randomness, which is what the term "circular polarizing filter" conjures up in my mind.

Post by **S8 Booster** » Sun Feb 23, 2003 11:00 pm

http://www.thkphoto.com/catalog/h/011pl.html